Ethylene polymerization using discrete nickel(II) iminophosphonamide complexes

摘要

The present invention generally relates to a new method of polymerizing ethylene. In one embodiment, the present invention relates to compounds utilized in the polymerization of ethylene and to a synthesis/polymerization method that uses same. In another embodiment, branched polyethylene is synthesized from an ethylene monomer using, in this embodiment, at least one nickel iminophosphonamide (PN2) complex. In still another embodiment, the reaction of (phenyl)(triphenylphosphine)(diphenyl-bis(trimethylsilylimino)phosphorato)-nickel, with Rh(acac) (C2H4)2 and ethylene yield a branched polyethylene. In an alternative of this embodiment, the reaction of (phenyl)(triphenylphosphine)(methyl-cis(trimethylsilyl)amino-bis(trimethylsilylimino)phosphorato)-nickel and ethylene, with or without Ni(COD)2, yields a branched polyethylene.

主权项

1. A method of polymerizing ethylene to form polyethylene, the method comprising the steps of:
(a) combining at least one ethylene monomer and at least one nickel catalyst selected from the following formulas: wherein R, R′ and R″ are independently selected from a C1 to C20 alkyl group, a C6 to C10 aryl group, a substituted C6 to C10 aryl group, and NR′″2 where at least one of R′ and R″ is NR′″2, wherein R′″ is independently selected from a C1 to C20 alkyl group, a C6 to C10 aryl group, a substituted C6 to C10 aryl group, and SiR′3; X is selected from a C1 to C20 alkyl group, a C6 to C10 aryl group, and a substituted C6 to C10 aryl group; and L is selected from a tertiary phosphine, a tertiary amine, nitrile, dialkyl sulfide, alkylaryl sulfide, and diaryl sulfide; or L and X together constitute a η3-benzyl or substituted η3-benzyl; and (b) polymerizing the mixture of Step (a) to yield at least one polyethylene polymer.